Woven roving fiberglass is one of the most widely used reinforcement fabrics in composite manufacturing, especially where high strength, structural stability, and durability are required. Known for its coarse weave and high fiber content, woven roving offers excellent mechanical properties and is commonly used in marine structures, tanks, FRP panels, wind turbine components, and industrial mold fabrication.

Understanding how it is made, its technical characteristics, and how it compares to other fiberglass fabrics helps buyers choose the right reinforcement for their application.

EWR E-glass Woven Roving

How Woven Roving Fiberglass is Made?

Woven roving is produced by weaving continuous fiberglass rovings into a bidirectional fabric. Each roving is a bundle of thousands of glass filaments, giving the fabric high tensile strength and structural reinforcement.

Production steps include:

• Roving preparation

Fiberglass rovings (typically E-glass or sometimes S-glass) are collected and wound onto beams. Their linear density determines the final gsm (gram per square meter) of the fabric.

• Weaving process

The rovings are interlaced in a plain weave or twill weave structure using industrial looms:

• Plain weave provides better dimensional stability and is more affordable.
• Twill weave offers higher drapability and smoother surface finish, often preferred for curved structures.

• Fabric finishing

After weaving, the fabric may receive:

• Sizing treatment to improve bonding with polyester, vinyl ester, or epoxy resins.
• Edge trimming for consistent roll width.
• Rolling and packaging to protect the fabric from moisture and contamination.

The result is a fabric with high fiber volume content and uniform strength in both warp and weft directions.

Features of Woven Roving Fiberglass

Woven roving has several characteristics that make it ideal for strengthening composite structures.

• High tensile and flexural strength

Because the fibers are continuous and aligned in two directions, the fabric significantly increases the laminate’s mechanical properties.

• Excellent thickness build-up

One layer of woven roving can add substantial thickness compared with chopped strand mat, reducing the number of layers required.

• Low resin absorption

The coarse weave reduces resin demand, meaning a lighter laminate without compromising strength.

• Fast wet-out

The open weave pattern enables resin to flow easily, speeding up lamination processes.

• Structural reinforcement

It is commonly used as a middle reinforcement layer with CSM on top for better bonding and surface finish.

• Available in various weights

Typical weights include 300g, 400g, 600g, 800g, and 1200g, allowing designers to control laminate thickness and strength efficiently.

These advantages make woven roving a reliable material for high-load, high-impact applications.

Woven Roving’s Difference from Other Fiberglass Fabrics

Woven roving stands out from other fiberglass reinforcements due to its structure, fiber orientation, and performance characteristics.

Woven Roving vs. Chopped Strand Mat (CSM)

• Structure: WR has continuous fibers; CSM uses short fibers.
• Strength: WR delivers far higher tensile and flexural strength.
• Surface quality: CSM provides smoother surfaces and better resin bonding between layers.
• Resin usage: WR absorbs less resin; CSM requires more.

Woven Roving vs. Biaxial Fabric

• Orientation: WR has 0°/90° fiber orientation; biaxial fabrics can be ±45°, 0/90°, or specialized directions.
• Drapability: Biaxial fabrics offer better draping for complex shapes.
• Mechanical performance: Biaxials often provide superior, more predictable strength due to stitched construction.

Woven Roving vs. Unidirectional Fabric

• Strength distribution: WR provides balanced strength in two directions; UD focuses strength mainly in one direction.
• Usage: WR is ideal for general reinforcement; UD is used where directional strength is critical (e.g., beams or spars).

Overall, woven roving is versatile and cost-effective but not as form-friendly as stitched reinforcements.

Is Woven Roving Better than Stitched Mat?

The answer depends on the application, as each material has distinct advantages.

Advantages of Woven Roving vs. Stitched Mat

• Higher tensile and flexural strength
• Lower resin consumption
• Better dimensional stability
• Great for thick laminate build-up
• More economical in structural applications

Advantages of Stitched Mat vs. Woven Roving

• Superior draping for complex shapes
• No crimping, leading to better load-bearing efficiency
• More uniform fiber distribution
• Often provides better fatigue resistance

Which one to choose?

Choose woven roving for:

• Marine hulls
• Flat or gently curved FRP panels
• Industrial tanks and pipes
• Large structural parts

Choose stitched mat for:

• Deep molds
• Curved or complex components
• High-performance composite structures requiring directional strength

Both materials can also be used together in hybrid laminates.

How to Store and Handle it Properly

Woven roving fiberglass should be protected from moisture, contamination, and physical damage to maintain its strength and bonding performance. It is best stored in a clean, dry environment with humidity below 70% and temperature between 15–30°C. Direct sunlight and heat sources should be avoided to prevent degradation of the sizing. Rolls are ideally kept upright or placed on storage racks to prevent deformation. When handling the fabric, clean gloves should be worn to avoid oil or dirt contamination. For optimal performance, woven roving should be used within its recommended shelf life, typically around 12 months.